如何从python中的json列表中提取特定数据

Question

I want to extract particular element from json list and I get my result from the code below:

result = CF.face.detect(img_url)

And when I print result I get:

[{u'faceRectangle': {u'width': 246, u'top': 196, u'height': 246, u'left': 113}}, {u'faceRectangle': {u'width': 217, u'top': 213, u'height': 217, u'left': 614}}]

Now if i want to get width of first faceRectangle I write:

print result['facerectangle']

and I recieve

TypeError: list indices must be integers, not str

How to fix it?

Answer 1

you result type is list so you need, get first element by index start from 0, and then you will have the dict and can get value by key:

print type(result)
print type(result[0])

print result[0]['faceRectangle']

Answer 2

如果需要第一个faceRectangle的宽度，则必须获取列表result[0]的第一个元素，然后是faceRectangle键result[0]['faceRectangle'] ，最后是宽度键result[0]['faceRectangle']['width'] 。

print result[0]['faceRectangle']['width']